Plan Now To Mininize Scours Next Spring

If you're thinking about implementing the Sandhills Calving System (SCS) for your 2008 calving season, now's the time to be contemplating your strategy and making those preparations, says Dave Smith, University of Nebraska-Lincoln (UNL) Extension veterinarian.

Named after the Sandhills area of north-central Nebraska where it was tested, SCS utilizes a series of calving pastures to minimize newborn calves' contact with disease agents. The idea is to minimize both the disease load and newborns' exposure to the disease agents until their immune systems are better able to withstand them.

"I like to say we're creating eight, one-week calving seasons rather than one, eight-week calving season," Smith says. "We're trying to recreate the conditions of the first week of calving season during each of the remaining weeks of the calving season. We want a clean calving area without the presence of older calves that may be shedding pathogens."

Neonatal calf scours is a multifactorial disease, Smith says. The ideal scenario for an outbreak is to have susceptible hosts (naïve calves) existing in an environment (infected communal calving area) that's conducive to the proliferation of (and continued exposure of the host to) the disease agent, be it E. coli, Salmonella, rotavirus, cryptosporidia, etc.

Smith says even the healthiest calf can fall prey -- particularly in the wet, muddy conditions common to spring calving periods -- if the pathogen load is high enough, or the exposure long enough, to overcome the passive immunity provided by the calf's mother.

SCS utilizes a series of calving pastures to minimize newborn calves' contact with disease agents. The idea is to minimize both the disease load and newborns' exposure to the disease agents until their immune systems have sufficiently matured to better withstand them. SCS consists of a series of large contiguous pastures. You can learn more specifics at: vetext.unl.edu/publications.shtml?to=Beef (click on "The Sandhills Calving System to Prevent Calf Scours"), but basically here's how it works:

Cows are turned into the first calving pasture as soon as the first calves are born, and calving continues for two weeks.

After two weeks, the cows that haven't calved are moved to Pasture 2, with cow-calf pairs remaining behind in Pasture 1.

After a week of calving in Pasture 2, the cows that haven't calved are moved to Pasture 3, and cow-calf pairs born in Pasture 2 remain in Pasture 2.

With each subsequent week, cows that haven't calved are moved to a new pasture, and pairs remain in their pasture of birth.

The result, Smith says, is a series of pastures that contain calves all born within one week of each other. Cattle from different pastures can be commingled after the youngest calf is four weeks of age.

The age segregation prevents pathogen transfer from older calves to the younger calves. And moving pregnant cows to new calving pastures helps minimize the pathogen load in the environment, as well as a newborn calf's exposure time to those pathogens.

Smith says the key component is the age segregation of calves and the movement to new pastures of cows that haven't calved, rather than moving pairs.

But adopting the system that requires multiple calving pastures vs. a single traditional calving yard necessitates some planning early on, Smith says.

"October is a good time to get started, because that's when a lot of herds are doing their reproductive exams and considering their calving and winter-feeding strategies," Smith says.

Among Smith's recommendations are:

Plan the pastures you'll use for calving and stockpile some forage on those pastures. The standing forage will help disperse the animals on those pastures and minimize the concentration of pathogens.

Consider your herd's anticipated calving times. Calving typically begins with a few early calves, followed by a peak when most calving takes place, and finishing with a long tail-off period for stragglers.

"Look at your herd's historical calving experience. You need to start thinking about what you need in terms of pastures and when during the season you will need them," Smith says.

For instance, if your herd's calving history is that a big influx of calves tends to arrive about the third week of the calving season, plan to utilize your largest pasture for that group, he says. "What you're trying to do is match cow numbers to the available ground. You don't want to overstock and damage the ground."

Consider your locale's typical winter-weather patterns. While it isn't possible to predict winter storms, Smith says most operators have a general idea of climate patterns for their area.

"Particularly for your earliest-born calves, which run the greatest risk of being born in potentially troublesome weather, identify and plan to utilize pastures that offer animals some additional shelter," Smith says. "That could be a row of trees or hills, something you're comfortable about having your cows in if there's a storm."

In addition, he says producers should draw up an emergency plan for really serious winter weather.

"Identify a place for cattle to go for shelter in those extreme storm situations -- areas to which they can have relatively ready access. You might not need to implement the plan every year, but there's some comfort in having planned for that blizzard of the century," Smith says.

In implementing SCS, realize that you're trading some labor. While a properly designed and implemented SCS can carry some huge dividends in minimizing calf scours, there are a few costs to the system, Smith says. Among them is the time spent getting feed to those animals.

"Instead of spending time treating scouring calves later on, SCS will entail more work early because your cattle will be spread out. That means you'll likely spend more time delivering feed to those areas and monitoring those groups than you would in a traditional calving yard. I think most ranchers would rather deliver feed than deal with scours, but it's a labor obligation that must be recognized and considered upfront," he says. "And be sure to vary your feeding locations within each pasture in order to disperse the pathogen load."

While SCS was designed for beef operations typical of western Nebraska -- larger herds on larger acreages, Smith says the age segregation of calves is the most important factor, not the number of acres or stocking density. Thus, the system should work for smaller herds on smaller acreages.

A better determinant for implementing SCS, he says, is your herd's calving history.

"If scours are a problem on your operation, SCS is one approach to beating the problem. But if you're not having losses due to scours, you probably shouldn't change what you're doing.

"In addition, if you have major concerns about weather because you calve in January, or about calving problems in your herd, SCS may not be the system for you because it does present greater challenges for those issues."

The main thing, Smith says, is to adhere to the SCS principles of clean pastures and age segregation of calves.

"There's nothing magical at work here. SCS just applies some principles about infectious disease control. Cutting corners to simplify the system, such as not properly segregating calves, violates the principles and compromises the results."

Smith encourages producers interested in implementing SCS to do so in cooperation with their herd-health veterinarian.

"It really helps, because SCS strives to apply medical principles to calving. Most ranchers are pretty sharp on these things, but having a veterinarian as part of the planning process is a big help," he says.